If radiation therapy is on your cancer treatment plan, being well-informed about what’s around the bend can alleviate worry and help you feel prepared for your treatment. To assist you, our radiation oncologists have answered the most commonly-asked questions about radiation therapy.

How does radiation therapy work?

Radiation therapy uses high-energy X-rays to kill cancer cells, using machines that can precisely target cancer anywhere in the body.

Radiation therapy is given either from the outside (external beam radiation therapy) or internally, through inserting sealed radioactive sources, like tiny thin tubes, into your body near the cancer. this is known as brachytherapy. Brachytherapy can be temporary or permanent (meaning the sources are left in your body to gradually disappear), depending on the type and location of your cancer.

Will it hurt?

External radiation therapy feels just like having an X-ray. You’ll hear a humming noise when the machine is on, but you can’t see, hear or smell the X-rays. After a few days, you might feel some soreness or discomfort in the treatment area.

Brachytherapy isn’t painful either, however you may feel a little discomfort from the implant and, depending on where it is inserted, you may be given a general or local anaesthetic.

Will I be radioactive?

You won’t become radioactive from external radiation, so rest assured you can have contact with with family members, children and pregnant women after each treatment session.

Brachytherapy implants may send radiation outside your body, so there may be limits on visitors while the implant is in place. Once the implant is removed you are no longer radioactive.

What will happen during my treatment?

External radiation therapy involves lying still on the treatment couch while a large machine known as a linear accelerator moves around you, directing X-rays towards the cancer. To help you lay still, we may customise a body mould for you, use head, arm or leg rests or even a face mask to stabilise your head.

We may need to make a few tiny dots on your skin with ink, marker pen or a tiny permanent tattoo, to line up with the laser lights and ensure the exact positioning of the machine. You will also see the red or green laser lights on your skin that help the radiation therapists position you correctly.

External radiation is usually given once per day over several weeks, depending on what type of cancer you have. Each treatment typically takes a few minutes.

Brachytherapy involves the positioning of tiny radioactive sources inside your body with the help of imaging scans. The treatment time may vary – high doses are delivered for a few minutes at a time over multiple sessions, and low-rate doses can be delivered over a period of 1-6 days.

What are the side effects?

Common side effects of radiation therapy can include fatigue and skin redness, which most patients experience to some degree. Other side effects can vary depending on the dosage and area being treated, and can include nausea, digestive problems, hair loss, cough or shortness of breath. Most side-effects will gradually subside after treatment has finished. Your radiation oncologist will thoroughly explain any possible side effects to you in detail before your treatment begins.

Why do I have to have so many imaging scans?

Your doctors need to plan your treatment carefully with a series of scans called a ‘planning CT’. These scans will determine the exact size and position of the tumour, and if other structures such as lymph nodes are involved. We willneed to scan you in different positions, such as with your arms above your head, lying on your back or on your stomach, to work out how to optimally deliver the X-rays. At this point, we will place tiny tattoos or dots on your skin that will help us to set you up in the exact position every treatment. On the planning CT, we outline which areas need to be treated, calculate the angles the X-ray beams will need to come from, and finally calculate the dose.

Where can I get further information?

You can find more information in our booklet ‘Explaining Radiation Oncology’, located in all patient waiting areas and the Radiation Oncology department.

We also provide a range of Cancer Council brochures in waiting areas, as well as ‘Radiation Oncology – Targeting Cancer’ brochures.